Conveyor systems form an integral part of modern production facilities. Such systems are especially beneficial in the food processing and article packaging industries, where it is often desirable to move articles to and from different areas of the production facility to undergo various manufacturing/packaging operations. For example, many food manufactures require transportation of food items from a baking area to a position for final packaging. However, many of these items, such as breads and other baked goods require cooling prior to packaging. Additionally, these food products are often soft and fragile, thereby requiring special care during transportation through the production facility to avoid damage.
In this regard, conveyor chains with rows of laterally repeating modular links forming the conveying surface are perhaps the most popular on the market today. Such a conveying surface does not, however, maximize the amount of thermal transfer to the underside of the articles being conveyed. This can be deleterious for cooling items during conveyance, such as baked goods or frozen foods being packaged at a downstream location. Soft goods also tend to conform to the conveying surface, if interrupted, which can lead to unwanted vestiges.
Another limitation with prior art chains with laterally repeating links is the creation of multiple crevasses and recesses in which debris and residue can become lodged. Despite the existence of various types of belt or chain “washers,” it remains difficult to ensure that the cleaning is as thorough as possible in view of the large number of open spaces in the conveying surface of a typical modular link chain. Such thorough cleaning may be crucial in certain situations (such as food processing), but may also contribute substantially to the operating expense.
Additionally, many production facilities also have limited floor space, thereby making efficient use of the space available imperative. Thus, manufacturers are increasingly desirous of conveyor systems occupying as small an area as possible. To do so, the conveyor chain must have the capability to move product smoothly around curves (including along a helical or spiral path), as well as along extended runs.
In the past, others have proposed linear conveyors incorporating slats, such as for use in applications involving the freezing of products. An early example is found in U.S. Pat. No. 3,447,668 to Jernigan, which discloses an endless conveyor formed of a plurality of thermally conductive (metal) elements designed to form a substantially planar conveying surface along the forward run. Along the return run, the elements pivot to a generally vertical position. This allows the thermal media (cold air) to reach the underside of the elements of the forward run and facilitate cooling of the articles being conveyed via the conductive element.
While this approach is advantageous in certain respects, it is not without significant limitations. For one, the conveyor is incapable of side flexing and, thus, can only assume a linear condition. This greatly limits its usefulness (including in connection with spiral-type freeze conveyors). Another limitation is that the elements are in direct contact along the forward run, and are thus subject to frictional wear. The free, uncontrolled pivoting of the elements may also render them susceptible to reaching undesirable positions and becoming “caught up” with adjacent elements.
Accordingly, a need is identified for a conveyor chain with a conveying surface capable of providing full, even support for any articles being conveyed, including smaller ones that might normally pass through or become caught within an open conveying surface. The conveyor chain would also be easy to clean and capable of negotiating turns or bends, thus potentially creating a savings in the amount of floor space occupied in the production facility. Overall, a substantial improvement in terms of efficiency and operator satisfaction would result, especially when used in conveying food products or other articles to be cooled during conveyance.